Pastor Jack Schaap formerly of First Baptist Church of Hammond, IN during this undated file photo. | (Photo: www.fbchammond.com)

Jack Schaap, the former pastor of First Baptist Church in Hammond, Ind., pleaded guilty in federal court on Wednesday in a case stemming from his sexual involvement with a teen girl, but has denied knowing that taking her across state lines for sex was illegal.

"I was not aware of the law," Schaap said before the court in Hammond, but said that he knew that his actions were "sinful and wrong."

The former pastor of the 15,000-member church, which he served for 11 years, stood accused of having sexual relations with the girl, a parish member who is now 17, and taking her across state lines to Illinois and western Michigan for the sexual encounters. Schaap and the girl started the affair when she was 16.

U.S. District Judge Rudy Lozano scheduled the sentencing for Jan. 15, although Schaap, 54, has already signed a plea agreement stating that he faces at least 10 years in prison for taking a person under 18 across state lines for sex, although the maximum sentence for such a crime could be life imprisonment.

The former pastor, described by the Southtown Star as wearing an orange prison garb while standing before the court, admitted to taking three trips with the teen across state lines for sexual activity, and said someone else actually drove the girl to the destinations.

The married father of two was removed from his position at First Baptist Church last month after a deacon apparently found a text message on his cell phone that showed the pastor and the girl kissing. Schaap had even been counseling the girl, it was revealed.

The investigation against Schaap by the FBI and the Lake County Sheriff's office also noted that the girl, who has not been named, had been taking classes at Hyles-Anderson College, where the former pastor once served as vice president.

The Indiana church is still looking for a new senior pastor to replace Schaap full time, but a spokesman for the church previously told CP that the congregation was handling the situation well and agreed with senior staff who dismissed the former pastor as soon as the allegations came to light.

"The church is actually more unified today than it ever has been," said Eddie Wilson, spokesperson and public relations director. "There's a sense of commitment on the member part to see that the church goes forward. We are 125 years old, a big congregation, and they are all very committed to making sure that the church succeeds. You get a real sense of unity, commitment, hope – it's not all doom and gloom. The past two Sunday services have been exciting, they have been powerful."